The present invention is directed to a device for filling prefabricated cigarette tubes, especially filter-tipped cigarette tubes, with tobacco.
There are a number of more or less convenient devices of the specified kind, all of the commonly used devices having an elongated pressing chamber which is defined on one side by an approximately semi-circular fixed wall portion and on the other side by an opposed semi-circular surface of a movable pressing beam by means of which the pressing chamber can be closed after having been filled with tobacco to result in a rod-like tobacco supply. On one end face of the pressing chamber there is provided a socket for application and fitting thereon of an empty cigarette tube. At the opposite end the pressing chamber is defined by a plunger-like tobacco ejector by means of which the tobacco supply may be transferred from the pressing chamber into the cigarette tube (cf. for instance DE-A-2,833,681; DE-C-2,139,242; DE-C-2,064,641; AT-A-146,213; FR-A-427,582; U.S. Pat. No. 638,904 or DE-A-3,135,700). To ensure safe operation, the devices commonly employed today also have a half-shell like spoon mounted on the effective end of the ejector bar for promoting or even enabling the transfer of the tobacco supply from the pressing chamber into the cigarette tube while at the same time maintaining the stability of the latter.
These known filling devices have proven more or less satisfactory in practical use. However, they exhibit the drawback that transfer of the tobacco from the pressing chamber into the cigarette paper tube has not been solved sufficiently satisfactorily by all of the prior known structural features. Among other things, they exhibit the drawback that upon filling of the tobacco pressing chamber the user must always take care to have as little tobacco fibres as possible project from the edge of the filling opening, because it happens frequently that during further handling a considerable number of the projecting tobacco fibres get jammed between the pressing beam and the edge of the filling opening opposite thereto, whereby reliable ejection of the tobacco rod from the pressing chamber and transfer thereof into the cigarette tube can no longer be ensured. In some cases the jammed tobacco fibres will hamper ejection of the tobacco rod to such an extent that the latter is upset longitudinally within the tobacco pressing chamber, and consequently the cigarette tube will either be filled but incompletely or, when the upset and therefore highly compressed tobacco supply is transferred, will break away from the fitting socket, in which case most cigarette tubes will burst and the ejected tobacco will crumble accordingly. Until recently, it was attempted to eliminate this problem by designing the upper edge of the pressing beam as cutting edge so that projecting tobacco fibres are cut off when the tobacco is compressed. But so far the corresponding measures have not proven sufficiently adequate, which is due to some extent to the existing tolerances and the materials normally used for the casing on the one hand, and the pressing beam, on the other hand.